A known internal combustion engine fuel injector comprises a tubular injector body extending along a given axis; and a valve housed in a seat in the injector body and comprising a tubular valve body fixed inside the injector body seat and coaxial with the injector body. The injector has an annular chamber defined by the injector body and the valve body, which have respective annular shoulders separated by a given distance equal to the height of the annular chamber.
To form the injector, the valve body is fixed to the injector body in a given position along the axis by means of further shoulders formed on the valve and injector bodies and resting against each other, and by means of a ring nut which engages a threaded portion of the injector body and pushes the valve body axially against the injector body to keep the further shoulders in contact with each other. The injector also comprises a seal housed inside the annular chamber to prevent the high-pressure fuel fed into the annular chamber from leaking between the injector body and the valve body.
The method of producing the above injector comprises forming shoulders on the injector body and valve body to form the annular chamber; threading a portion of the injector body; forming further shoulders on the valve body and injector body to define a given axial position of the valve body with respect to the injector body; and assembling a seal and ring nut.